Recently we completed a population-based case-control study of endometrial cancer in which diet was assessed for 482 Caucasian, African American, and Latina cases and 460 controls residing in the San Francisco Bay area. Here we propose to use this previously collected data to address several emerging or unresolved hypotheses related to the impact of plant foods on endometrial cancer risk. In each case, our hypotheses are based on how dietary components may affect metabolic pathways that are or may be important in endometrial carcinogenesis, i.e., those involved in steroid hormone and insulin metabolism. Our specific aims are to evaluate the relationship between endometrial cancer risk and (a) cruciferous vegetables isothiocyanates, (b) various measures of dietary antioxidants, (c) whole grains / dietary fiber, (d) refined grains / glycemic load, and (e) dietary patterns. Our case-control study included women diagnosed with histologically-confirmed endometrial cancer between October 1, 1996 and September 30, 1999. Cases were identified through a population-based cancer registry which is part of the SEER and California state programs. Controls were identified through random-digit dialing and frequency-matched to cases on age and race/ethnicity. Women with a prior hysterectomy were not eligible as controls. Diet was assessed using a 100-item food-frequency questionnaire (FFQ) and visual aids to assess portion size. Interviews were conducted in English and Spanish by professional bilingual, bicultural interviewers. As part of the proposed project, we will use unconditional logistic regression analyses to estimate the relative risk (i.e., odds ratios and 95% confidence intervals) of endometrial cancer associated with the food groups, non-nutritive compounds, indices of antioxidant and glycemic exposure, and dietary patterns of interest. A priori definitions and factor analysis will be used to identify dietary patterns. The results of the proposed analyses will provide further understanding of the etiology of endometrial cancer.